Discover the truth about the Special Demonstration Squad, a top-secret operation to monitor British ‘subversives’.

The purpose of the organisation was to keep tabs on environmental activists, anti-racism groups and animal rights campaigners.

Award-winning investigative journalist Rob Evans, co-author of Undercover, and lawyer Harriet Wistrich, currently representing eight women who are bringing a civil claim against the Metropolitan police for emotional trauma after having relationships with undercover policemen, discuss the psychological challenges and the human cost of a lifetime of deception – and whether it can ever be justified.